i think this is a 350..numbers from the pad.

16J144121 710066MJ

Partial Vin:
1=Chevrolet
6=1976
J=Janesville vehicle assembly plant
144121=Car Sequence number

Engine ID:
7=? probably T=Tonawanda engine plant
1006=Oct 6th engine assembly date
6MJ=?? May be CMJ='76 Impala 350/145hp 2bl L-65

Rene
66_Malibu

thanks!!